I have often wondered how “relative” meters are. Like maybe relying on one meter and learning how you feel at 40, 70, 100, 150, etc. and that is what is important. (I recognize this is not how it’s suppose to work, but I have wondered if this is how it works.)
I think that’s important. I tested immediately after this photo again with the one-touch and it said 206… so yep a 100+ pt spread
It makes no sense whatsoever but it almost seems as if the one touch detects spikes earlier than other finger stick meters… it’s really strange
I know that in regards to callibrating Dexcom, tech support advises using only one meter, as using different meters can mess up Dexcom’s readings.
I would at least stick to one type of strip. I use a Contour Next One as my main meter and have a Next and a Next USB as backup. I just tested on all three meters using the same drop of blood and got 7.9, 8.0, and 8.3 mmol/L (142, 144, 149 mg/dl).
I always calibrate with the one touch… it makes sense that more than one meter would mess it up… although as worthless as it and all my other meters seem to be, hard to imagine how it could make it much worse
My Dexcom matches up really well with my meter readings. My Dexcom is currently reading 7.3 mmol/L with an up arrow, which is pretty close to those meter readings. Often when I callibrate, my meter will give the same BG as the Dexcom is showing. This isn’t always the case, of course, but I also run my sensors for a month on average, so I chalk up a lot of the inaccuracies I may get later on to sensor age.
My dexcom is only ever remotely close if I’m fasting
Do you use Afrezza a lot? I know my Dexcom can’t keep up if I’m having very rapid changes in my readings.
Not lately… although it does add some cgm issues, it’s really not a primary factor in the cgm not working well for me
I don’t know why it’s so easy for me, but my Contour Next One is almost always within 10-15% of the Dexcom, and my A1c invariably matches what the Dexcom (xDrip+) estimates. Also, I do not use more than one Bg meter at a time. That would be cause for insanity.
That being said, there are infrequent instances when the meter and the Dexcom are pretty far off.
This is generally how my primary meter and Dexcom work for me. My A1c is always lower though. Even when I test on two different meters, they’re almost always within a decent range of each other. I’ve tried it a couple times over the last few days with my verio flex and my contour next. Always no more than 10 points away from each other.
I’d like to know why some people have more trouble with this than others.
Yeah, it seems there are some people CGMs just don’t work well for.
So would I…
If I’m fasting and my bg is stable and in normal/ low ranges everything lines up reasonably well. If anything’s actually happening everything is way off. One thing that occurred to me to ponder is the last time I had labs done my sodium was slightly low, out of the reference range… seems to me like that could certainly be a factor that could affect some strips differently
Eg salt water has very different electrical conductivity than fresh water
Found an answer!!! When you mentioned elevation the other day, you were definitely onto something!
“Figure 8 shows the effect of altitude when mountain climbers checked their blood glucose at 13,500 ft.7 As expected, the electrochemical glucose oxidase meters (One Touch® Ultra® and Precision® X-tra®) overestimate the glucose by 6% to 15%, whereas the glucose dehydrogenase meters (Ascensia® Contour, AccuChek® Complete®, and Abbott® Freestyle®) were all within 5%.”
How far are you above sea level? The highest point in DC is only 410 feet above sea level.
Not far at all… comparable.
I spend lot of time at sea level
I guess so. I forgot about your job.
I think a lot of the factors are likely physiological, especially in terms of how the Dexcom performs given that it’s using interstitial fluid to approximate blood glucose levels. I also suspect some factors may overlap between accuracy and what determines the extent to which people can successfully extend sensor life—seems like the people who experience greater accuracy on average also tend to be the ones who can extend their sensor lives the longest. We know being skinny/having less subcutaneous fat makes the Dex flakier, and I’m guessing there are a number of as of yet unidentified physiological moderators as well, perhaps charectestics of body tissues, immune function/inflammatory response, who knows.
This has actually changed a lot for me as time has gone on. I used to not get an average of perhaps 15-16 days from my sensors. Over the years I’ve extended that to a month on average. I think it’s been a combination of taking more allergy medications (less overall inflammation), switching to a very low-carb diet so that my blood sugars are much more steady, and layering Opsite Flexifix tape over top of sensors as they start to become loose (but before they’re falling off) to reduce motion. I also do have a fair bit of subcutaneous fat, so I’m sure this helps out as well. The biggest jump came with my diet change, though, and it’s partly what keeps me motivated to continue.
Yesterday I went from sea level to 7,160 ft and ate lunch at 6,069 ft but I think my meter was accurate enough
Back to @Sam’s complaint. When I used a Verio to calibrate my CGM, my CGM readings were a wild and it never seemed like the meter and the CGM would match.
When I changed to the Contour Next, it was amazing - the CGM is always close to my meter readings, especially when my line is flat. The Contour Next make my CGM a lot more useful to me. I only get issues during intense exercise, the readings drop appropriately with my BG drop but they can be a bit slow to recover from a low blood sugar.
I can easily get 3-weeks out of a sensor and I only change my sensors because the tape starts to peel up or I want to rotate the site because it has been stuck to me for too long.